fix: add null guards for output.output in tool.execute.after hooks

src/hooks/comment-checker/hook.output-guard.test.ts

@@ -0,0 +1,24 @@
+import { describe, it, expect, mock } from "bun:test"
+
+mock.module("./cli-runner", () => ({
+  initializeCommentCheckerCli: () => {},
+  getCommentCheckerCliPathPromise: () => Promise.resolve("/tmp/fake-comment-checker"),
+  isCliPathUsable: () => true,
+  processWithCli: async () => {},
+  processApplyPatchEditsWithCli: async () => {},
+}))
+
+const { createCommentCheckerHooks } = await import("./hook")
+
+describe("comment-checker output guard", () => {
+  //#given output.output is undefined
+  //#when tool.execute.after is called
+  //#then should return without throwing
+  it("should not throw when output.output is undefined", async () => {
+    const hooks = createCommentCheckerHooks()
+    const input = { tool: "Write", sessionID: "ses_test", callID: "call_test" }
+    const output = { title: "ok", output: undefined as unknown as string, metadata: {} }
+
+    await expect(hooks["tool.execute.after"](input, output)).resolves.toBeUndefined()
+  })
+})

src/hooks/comment-checker/hook.ts

@@ -89,6 +89,8 @@ export function createCommentCheckerHooks(config?: CommentCheckerConfig) {
     ): Promise<void> => {
       debugLog("tool.execute.after:", { tool: input.tool, callID: input.callID })
 
+      if (!output.output || typeof output.output !== "string") return
+
       const toolLower = input.tool.toLowerCase()
 
       // Only skip if the output indicates a tool execution failure

src/hooks/edit-error-recovery/hook.ts

@@ -43,6 +43,7 @@ export function createEditErrorRecoveryHook(_ctx: PluginInput) {
       output: { title: string; output: string; metadata: unknown }
     ) => {
       if (input.tool.toLowerCase() !== "edit") return
+      if (!output.output || typeof output.output !== "string") return
 
       const outputLower = output.output.toLowerCase()
       const hasEditError = EDIT_ERROR_PATTERNS.some((pattern) =>

src/hooks/edit-error-recovery/index.test.ts

@@ -21,6 +21,17 @@ describe("createEditErrorRecoveryHook", () => {
       metadata: {},
     })
 
+    describe("#given output.output is undefined", () => {
+      //#when tool.execute.after is called
+      //#then should return without throwing
+      it("#then should not throw", async () => {
+        const input = createInput("Edit")
+        const output = { title: "Edit", output: undefined as unknown as string, metadata: {} }
+
+        await expect(hook["tool.execute.after"](input, output)).resolves.toBeUndefined()
+      })
+    })
+
     describe("#given Edit tool with oldString/newString same error", () => {
       describe("#when the error message is detected", () => {
         it("#then should append the recovery reminder", async () => {

src/hooks/task-resume-info/hook.test.ts

@@ -0,0 +1,17 @@
+import { describe, it, expect } from "bun:test"
+import { createTaskResumeInfoHook } from "./hook"
+
+describe("createTaskResumeInfoHook", () => {
+  describe("tool.execute.after", () => {
+    //#given output.output is undefined
+    //#when tool.execute.after is called
+    //#then should return without throwing
+    it("should not throw when output.output is undefined", async () => {
+      const hook = createTaskResumeInfoHook()
+      const input = { tool: "Task", sessionID: "ses_test", callID: "call_test" }
+      const output = { title: "Result", output: undefined as unknown as string, metadata: {} }
+
+      await expect(hook["tool.execute.after"](input, output)).resolves.toBeUndefined()
+    })
+  })
+})

src/hooks/task-resume-info/hook.ts

@@ -21,6 +21,7 @@ export function createTaskResumeInfoHook() {
     output: { title: string; output: string; metadata: unknown }
   ) => {
     if (!TARGET_TOOLS.includes(input.tool)) return
+    if (!output.output || typeof output.output !== "string") return
     if (output.output.startsWith("Error:") || output.output.startsWith("Failed")) return
     if (output.output.includes("\nto continue:")) return